We are studying the mechanisms involved in bacterial motility and chemotaxis. By isolating specific genes that regulate these processes in E. coli, we have been able to define the nature of the gene products. We have determined the manner in which these products are localized in the cell. We are currently isolating four polypeptides that are integral membrane components. Two polypeptides are necessary for chemotaxis and the other two are required for motility. We plan to purify and characterize these proteins and to determine how they function by doing reconstruction experiments with lipid bilayers and with membrane vesicles.